50 amp power center to replace subpanel?

[StillCampin]

Calling all customizers, esp those with electrical experience... If you foresee a problem with this idea please let me know now while I'm in the idea stage.

My 5.0 gets delivered at the end of Aug. Some of you may recall some of my earlier posts indicating that I'll be doing extensive electrical changes. As part of these changes, I'll be going with Lithium batteries to begin with.

Since these batteries require a different charge profile than lead-acid batteries, I need to upgrade the charging section of the converter. My research indicates that my two choices are to replace the charging section only or replace the whole power center. It turns out that the cost for the charging section only is very similar to a totally new power center. I've replaced a power center before so I have no qualms about the work, tho I'll have to do some measuring before ordering to ensure it would fit without drastic changes.

I am seriously considering a 50 amp power center (with Lithium charging section) that is almost the same face dimensions as what ETI puts in. Being 50 amp it has 2 buss bars in it. If I go this route I would totally remove the subpanel ETI puts in for "whole house" inverter use and use the second buss bar for this purpose.

If I stay with a 30 amp cord this move of the subpanel breakers to the second buss is essentially the only related electrical change. By going with a dual buss power center I eliminate 1 box and open up additional breaker positions for my new circuits.

If I ever decide to move to a 50 amp cord with 2 hot lines it would be just a minor wiring change to accommodate, tho a new EMS would be needed.

Going with the dual buss power center will also allow me to have the potential to easily put the inverter output to both buss bars by wiring 2 breakers together. If I ever did this I believe that I would want to put a relay between the breakers controlled by the inverter so that the two hots never get combined when connected to shore power.

[Brian B-P]

I think this makes sense, but if you are willing to go to separate components the split 30/30 version of the Progressive Dynamics PD5500 series might be more suitable than any 50-amp version, because it has a left/right split rather than interleaved buses. See "Stab Configuration" #3 in the PD5500 Configuration Options guide; this would be a PD55K003. I don't think these configuration options are available for the distribution panel within an integrated power centre.

If you are seriously considering a future addition of 240 V / 50 amp service, but still with a separate section for inverter output, you could consider configurations #5 or #6 in that guide.

With separate components you would still need a DC distribution (fuse) panel; the complementary panel is the PD6000 series.

While the integrated power centres make both technical and economic sense and are tidy to install, once some portion doesn't fit your needs it can make more sense to me to use separate components, each suited to your specific requirements.

My motorhome came with these separate panels (and PD9260 converter/charger), but the panel just has ordinary interleaved buses for 240 V service and no provision for a dedicated inverter-powered section. This allowed them to mount the converter/charger in a different location which they preferred.

[StillCampin]

Originally Posted by Brian B-P

the split 30/30 version of the Progressive Dynamics PD5500 series might be more suitable than any 50-amp version, because it has a left/right split rather than interleaved buses.

Thank you - I didn't even think about a split buss and that type of configuration does make a lot sense for inverter use over an every-other-one configuration.

More research for me such as check the cut-out size and decide on a configuration. Something to do as I'm counting down the days.

I see you kept adding to your post.

[StillCampin]

Upon further consideration, tho the tab configuration would be great, actually doing a split with separate AC & DC panels and still needing a converter and Lithium specific charger (even if the DC panel was part of the converter & charger) looks to be beyond what I want to do as a retrofit when I consider all the other changes/additions I'll be doing under the seat bases. I want to leave some storage space.

[Brian B-P]

Originally Posted by StillCampin

I want to leave some storage space.

The panels are not very deep, so the space behind them is still available... but yes, two panels cover more area and the converter/charger would need to sit somewhere, presumably behind the panel sticking into the storage space as the bottom of the power centre does.

[StillCampin]

If I had all dimensions and could do a mockup of the space, even just on paper, I might pursue separate devices but my research has indicated to me that, tho I could likely get the "perfect" combination, it would end up costing more in dollars, space & effort to go that route than a combination unit.

The PD4560L 50 Amp Power Center with 60 Amp Lithium Converter/Charger appears to have everything I'm looking for including a left-right double buss instead of interleaved like the usual 240 volt ac panel. This fits my idea for using the second buss for the inverter circuits; I just may want to install a separate neutraI bar (?). It is also almost the same dimension as the unit ETI installs so very little hole modification will be needed, tho it will be turned vertical instead of horizontal.

[Vermilye]

Originally Posted by StillCampin

If I had all dimensions and could do a mockup of the space, even just on paper, I might pursue separate devices but my research has indicated to me that, tho I could likely get the "perfect" combination, it would end up costing more in dollars, space & effort to go that route than a combination unit.

The PD4560L 50 Amp Power Center with 60 Amp Lithium Converter/Charger appears to have everything I'm looking for including a left-right double buss instead of interleaved like the usual 240 volt ac panel. This fits my idea for using the second buss for the inverter circuits; I just may want to install a separate neutraI bar (?). It is also almost the same dimension as the unit ETI installs so very little hole modification will be needed, tho it will be turned vertical instead of horizontal.

Don't know if is a consideration, but a lithium charger will output the full current of the converter until full. Be sure the 12V wiring & the 120V power source is up to the job.

[Brian B-P]

Originally Posted by StillCampin

The PD4560L 50 Amp Power Center with 60 Amp Lithium Converter/Charger appears to have everything I'm looking for including a left-right double buss instead of interleaved like the usual 240 volt ac panel. This fits my idea for using the second buss for the inverter circuits; I just may want to install a separate neutraI bar (?).

Excellent find! I'm surprised to see the centre-pivoted and non-interleaved design. I guess they decided that almost no one uses 240 V circuits in an RV (although it can be done with the standard 50-amp campsite service), so there was no need to interleave them. Feeding it with a single 30 amp breaker instead of the stock 50 amp double breaker, I agree this would be a nice match.

Transfer switches do normally switch the neutral, so splitting the neutral bus seems appropriate.

https://www.progressivedyn.com/rv/power-centers/inteli-power-4500-series/

[StillCampin]

Originally Posted by Vermilye

Don't know if is a consideration, but a lithium charger will output the full current of the converter until full. Be sure the 12V wiring & the 120V power source is up to the job.

A 60 amp charger wasn't part of my initial expectations so I'll have to upgrade the 50 amp fuse I currently have but the #4 wire I've been intending between the converter & the fuse should still be OK. I have some #2 for another purpose that will result in some excess after installation of what it's for so I could upgrade.

The install manual indicates a 15 amp ac breaker for the converter. If needed, my 2000 watt Honda should do it but will get a workout and I won't be able to do anything else with it until the batteries are fully charged - but at least they charge (relatively) fast.

An interesting thing about the converter section itself: the specs show a total of 120 amp output, 60 to the battery leaving 60 for the 12v distribution panel. Definately different from my current setup with a much smaller total output where the charging only gets what other things are not using.

[Brian B-P]

Originally Posted by StillCampin

An interesting thing about the converter section itself: the specs show a total of 120 amp output, 60 to the battery leaving 60 for the 12v distribution panel. Definately different from my current setup with a much smaller total output where the charging only gets what other things are not using.

But the converter/charger (existing or new) has only a single output, because the distribution panel and battery are not separate, so the converter/charger doesn't know or control where the current goes. The rate of battery charge (or discharge) is simply the difference between what the converter/charger is producing and the total of what everything on every circuit is using.

What I see in the specs on the product page and on the manual is simply a total output of 60 amps. When they say "The full rated load is available for load, battery
charging or both", I'm sure they simply mean that it doesn't matter where the 60 amps is going... and that's not really a product feature, just the reality of the load and battery being connected.

The output of the 60 amp unit goes through a set of fuses rated at only 75 amps total, not two outputs fused at 60 amps or more each.

[Brian B-P]

Originally Posted by StillCampin

The install manual indicates a 15 amp ac breaker for the converter. If needed, my 2000 watt Honda should do it but will get a workout and I won't be able to do anything else with it until the batteries are fully charged - but at least they charge (relatively) fast.

That's not a problem. 60 amps at 14.6 volts is only 846 watts; due to imperfect efficiency, the input power is higher, but it is still specified as only 1000 watts. 1000 watts at 120 volts is 8.3 amps; it will never use the full 15 amps, or even the 80% of that or whatever fraction is allowed for continuous loads.

[StillCampin]

I think you are correct but I'll explain where I got my numbers. "DC section" spec shows '120 amp max'. "Converter section" spec shows 60 amp. The lithium charging is 60 amp. The numbers all went together when I considered converter spec and charging amps as separate, thus adding to the 120 max spec.

I guess I was assuming 120 dc total with a 60/60 split between charging & distribution.

[Brian B-P]

Originally Posted by StillCampin

I think you are correct but I'll explain where I got my numbers. "DC section" spec shows '120 amp max'...

I see, where you're going, but the DC section capacity is just what that fuse panel can handle in total. If you draw 120 amps from any combination of the DC circuits, up to 60 amps will be coming from the converter and the rest will be coming from the battery. Nothing stops you from drawing more, as more just comes from the battery (although not safeIy). If the converter is not on (no shore power), then all 120 amps will be coming from the battery.

This is a nice feature of systems (including essentially all current RV systems) which keep the battery always connected to the loads: peak load is not limited to what the converter can supply.